The three main export crops of Sri Lanka are tea, coconut, and rubber, the third most important crop. Rubber is a raw material used even for large-scale products. Farmers of the rubber industry in Sri Lanka make Various products through rubber. Besides milk, farmers use rubber plants as wood to make various products and rubber as fuel.
From trees to estates, expansion of the rubber industry in Sri Lanka
The scientific name of the rubber plant is Hevea brasiliensis. Farmers produce rubber mainly by using a white liquid they obtain when they cut the trunk of a specific type of tree. In common usage, we call that tree a rubber tree. The rubber plant belonging to the Hevea genus and Hevea Brasiliensis species of the Euphorbiaceal family lives on average for about 100 years. But even if you live this long, you can get the economic harvest for only 30 years. Harvesting starts on average five years after planting. In the dry zone, this can take up to 6 years.
History of the rubber industry
There are different stories about the discovery of rubber. History says that a woman who went to the forest to look for food saw a tree flowing with milk, took some of it, and started using rubber for the first time.
When Christopher Columbus first set foot in South America, he was amazed to see the rubber balls used by the South American tribes at that time to play, called “bolas” in Spanish, which immediately bounced back when hit.
And in 1736, an astronomer who went to Peru brought a sticky white liquid like honey. However, it was in 1839 that people started using rubber for industrial production. Because of Charles Goodyear, the current use of rubber begins.
How did rubber come to Sri Lanka?
In 1876, Henry Wickham brought a special collection of rubber seeds collected from the Amazon to Kew Gardens in London and planted them. A few plants grown from seeds belonging to two types of Brazilian rubber were brought to Ceylon and planted in Henarathgoda Park in 1876.
It is said in history that the yield given by the plants from Brazil planted in Sri Lanka in the early 1900s is about 75 kg per hectare per year. In 1909, the world’s first rubber research institute was established by the British on a Kalutara plantation in Sri Lanka to conduct tests on the use of latex from the rubber plantation planted in Henarathgoda.
What is rubber milk?
Various types of sap are produced by a species of laticiferous tissues found in many trees growing in tropical countries. These plants are protected from herbivores by their poisonous sap with a bitter taste. Also, resins, alkaloids, and other hydrocarbons, which are waste products of metabolism, are contained in the juice. The elasticity of rubber is due to its long chains of hydrocarbon molecules.
The traditional process of making rubber in Sri Lanka
By February, the leaves of the rubber trees grow and fall from the tree. After about three weeks, new leaves and flowers emerge. Farmers don’t milk them at that time when the tree pit has only leaves without leaves. Because of this, the villagers called the month of February ‘Rubber Leaf Holiday.’ Farmers often weed the land and fertilize the rubber trees at this time. To promote the creation of new tissue and the inhibition of bacteria, they simultaneously apply dung clay and a chemical liquid to the regions where the bark of the trees has been injured during milking.
Getting rubber milk from trees
After about five years of planting, a rubber tree can produce milk. For this, they make the first ‘cut’ at the height of about four feet from the tree’s base, about half the tree’s circumference. It is also essential to remove the metal strip and attach it to the new cut to fix the milk coconut shell and for the milk stream to flow.
Farmers use a specially prepared ‘milk knife’ for this purpose. This incision has an inclination of about 15 degrees for easy flow of the expressed milk. At the bottom of this cut, they attach a small metal “track” and make a shallow channel about a foot deep. The milk that spills from the cut flows down, falls into the trough along the stream, and collects in a coconut shell fixed between the supporting spout and the trunk of the tree by bending down a small part of the trough in the middle.
Cutting the tree’s bark to get them should also be milk carefully. The lactating mammary tissue is located in the secondary polyploidy tissue beneath the brown, woody bark of the tree. The villager is adept at adjusting the rubber cut so as not to damage the primary phloem, the growing tissue of the underlying tree.
Importance of time on taking the milk from rubber trees
It is customary to start cutting the latex as early in the morning as possible. Usually, there are about one hundred rubber trees in one ‘rubber lot.’ When the milking starts early in the morning, at around ten in the morning, ‘Kiri Akilima,’ or the milk that has flowed from tree to tree, is collected in a bucket. Farmers collect milk cans from all the trees in about an hour. The milk left on the tree’s cut thickens and forms like a curd on the cut at the time of milk collection. When farmers cut this ‘patta’ the next day, they remove it and collect it separately. They call this Patta species ‘Otta Pal.’
Farmers start the next step of the rubber production process from the collected milk. They strain the milk brought home or to the processing center through a strainer and pour it into specially prepared ‘trays’ to which a few spoonfuls of dilute acetic acid add a certain amount of water.
After that, they stir the milk well with a spoon. They remove the foam and keep it still. Farmers prepare one milk tray from the milk obtained from about twenty modern ‘budded’ rubber trees.
The acid-laced milk solidifies in about four hours, turning into a soft curd. For the production of rubber sheets, farmers crush and thin this curd. The small landowner often puts it on a plank and crushes it by hand. They thin it with a weighted bottle filled with gravel and prepare a raw ‘roti.’ People sometimes use hand-rotating ‘water rolls’ to crush the bread. After hammering, they further thinned raw ‘roti’ by passing it through a special device loaded with hand-rotating ‘diamond rolls.’ (They call it diamond because of the shapes formed by the edges arranged on both sides of the bread) Farmers call this process ‘Roti catching’. When this is over, most water is removed, and farmers obtain thin raw ‘Roti’ with edges.
Drying the ‘Amu Roti’ is the next task of the rubber farmer. The small rubber landowner uses his own smokehouse for this purpose. The’ smoke house’ is often a small room with a galvanized sheet roof covered with clay. In the rubber ‘smokehouse,’ they place the ‘raw roti’ on a fire grate suspended from crosswise poles. They put wood on fire below to smoke and dry. After smoking for two or three days, the ‘roti,’ completely dewatered, becomes light brown. They call these ‘sheet rubber.’ This imported ‘Sheet Rubber’ is known as ‘Smoked Dara Roti’ in the foreign market.
‘Smoked Dara Roti’ has excellent demand in the foreign market. It has been recommended that this type of rubber is especially suitable for producing tires and other materials that lead to wear and tear in vehicles.
Modern rubber production
Now rubber farmers produce rubber in two ways.
- Crepe rubber
- Smoked sheet rubber
Production of crepe rubber
Crepe rubber is the purest type of natural rubber currently available. This crepe rubber is used as a raw material to prepare dry rubber-related products such as hygienic surgical instruments, food contact rubber products, and gum. The steps in the production of crepe rubber can be outlined in a note as follows.
- Milk coagulation
- Pooling and standardization of latex
- Lace drying
- Determination of the percentage of dry rubber
- Basic filtering
- Field milk collection
- Safely protect the rubber
Production of smoked sheet rubber
What is the major form of rubber produced in Sri Lanka? Sheet rubber is the traditional and oldest type of rubber in Sri Lanka. More than half of the local minor rubber production is sheet rubber. Small and medium-scale rubber plantation owners dominate the production of sheet rubber. People use this sheet rubber as raw material in every product. They use it to manufacture sandals, bicycle tires, and airplane wheels. The steps in the production of this sheet rubber are as follows.
- Collecting and straining milk
- Sorting and storing sheets
- Sheet smoking
- Sheet pan drying
- Re-washing the milled sheets
- Grinding curd
- Preparation of curd
- Freezing milk
- Refrigerating the milk
- Adoption of milk
- Add acid and defoam
Rubber products – Rubber industry in Sri Lanka
Rubber production and rubber-related goods cover a significant percentage of the Sri Lankan economy. The rubber industry in Sri Lanka provides more than 300,000 direct and indirect employment opportunities within Sri Lanka.
- Sheet Rubber
- Crepe Rubber
- Pale Crepe
- Sole Crepe (Sole Rubber)
- Centrifuged Latex
- Ribbed Smoked Sheet
- Technically Specified Rubber
- Specialty Rubber
Various finishes are made in the factories using the finishes thus produced in the rubber manufacturing plant. If they are,
- Conveyor Belts
- Auto Parts
- Solid Tires
- Hot water bottles
- Gloves used for medical and surgical purposes
- Industrial equipment
Other rubber products
- Rubber bands
- Sporting goods
- Mattresses, carpets, cushions
Where is the famous for rubber in Sri Lanka?
In Sri Lanka, farmers grow rubber in the moist zone of the tropical lowlands below 1400 feet. There are two forms of rubber farming, depending on the area utilized. Smallholders are defined as those who own less than 8 hectares of land. Estates, in contrast, are plantations that are 8 hectares or larger.
The wet zone is home to most of Sri Lanka’s 127,500 hectares of rubber plantations. Sri Lanka’s primary rubber-growing regions are:
The natural rubber industry in Sri Lanka is the most successful, sustainable, and socio-economically viable asset by the imperialists. Being the first Asian country to cultivate rubber, Sri Lanka occupies a leading position in the world when considering the natural rubber industry. Sri Lanka’s natural rubber manufacturing sector has become the country’s third-largest foreign exchange earner.